Epidermal growth factor receptor EGFR specific mutations have been known to improve survival of patients with non-small-cell lung carcinoma NSCLC. However, whether there are any changes of EGFR mutations after targeted therapy and its clinical significance is unclear. This study was to identify the status of EGFR mutations after targeted therapy and predict the prognostic significance for NSCLC patients.

Methods

A total of forty-five 45 NSCLC patients who received EGFR-TKI therapy were enrolled. We identified the changes of EGFR mutations in plasma ctDNA by Amplification Refractory Mutation System ARMS PCR technology.

Results

In the 45 cases of NSCLC with EGFR mutations, the EGFR mutation status changed in 26 cases, in which, 12 cases 26.7% from positive to negative, and 14 cases 31.1% from T790M mutation negative to positive after TKI targeted therapy. The T790M occurance group had a shorter Progression -Free-Survival PFS than the groups of EGFR mutation undetected and EGFR mutation turned out to have no change after EGFR-TKI therapy p < 0.05.

Conclusions

According to this study, it’s necessary to closely monitor EGFR mutations during follow-up to predict the prognosis of NSCLC patients who are to receive the TKI targeted therapy.